Tank gauge



July l, 1958 F. M. MAYEs 2,841,009

TANK GAUGE Filed oct. 17, 1955 FRED M. MAYES -TTORNEYS TANK GAUGE Fred M. Mayes, Newtown, Pa., assignor to Sun Uil Cornpany, Philadelphia, Pa., a corporation of New Jersey Application October 17, 1955, Serial No. 540,728

1 Claim. (Cl. 73-321) This invention relates to tank gauges and particularly to such gauges for use in tanks having floating roofs.

In the case of iioating roof tanks which are not provided vvith large diameter wells in the roof for the installation of gauging oats it is customary to effect gauging by measurements of movements of the roofs which are directly attached to automatic gauges. Normally this attachment is at one point only, and to avoid construction of a truss to support the gauge wire over the center of the tank, the attachment of the gauge wire is generally near the edge of the tank. A direct error is thus introduced if the roof is tilted as is quite usually the case due to asymmetry of the roof and accumulation of water or `solid debris. It is a general object of the present invention to eliminate errors due to roof tilting while providing 4a very simple arrangement for effecting the gauging without the necessity for elaborate structural arrangements.

The general object of the invention as well as others relating to details will become apparent from the following description read in conjunction with the accompanying drawing in which the figure is a diagrammatic sectional view showing the application of the invention to the gauging of a floating roof tank.

A tank 2 is illustrated as provided with a roof 4 including buoyancy chambers 6 to cause it to oat on the oil or other liquid A containedrwithin the tank. Such a roof is generally arranged to catch and hold rain water indicated at B. IIn the event that the construction is asymmetric, the accumulation of water may cause tilting, and tilting will also be caused by the accumulation of dirt or debris on the roof.

To provide for accurate gauging, a gauge wire 8 is anchored at the upper portion of the tank wall as indicated at 10 and passes downwardly beneath a pulley 12 supported by the tank roof and then extends diametrically across the tank beneath a similar pulley 14 supported by the roof, from which last pulley it passes upwardly over the edge of the tank supported by pulleys i6 and 18 and then outside the tank to the gauging device indicated at 20. To avoid errors due to sag of the wire it may be supported by auxiliary pulleys 22 and 24 supported by the tank roof.

The gauge may be an automatic gauge or a direct reading gauge of any desired type, involving, for example, an adjustable potentiometer arrangement controlled by ICC movements of the wire 8. If most usual forms of gauges are used, the wire may extend directly across the space between the supporting pulleys indicated at 24. It will be evident that irrespective of the tilt of the roof, the wire in the region where it is attached to the gauge will have a movement which is twice that of the means position of the floating roof irrespective of the roof tilt.

Specifically shown in the figure is a modification which is adapt-ed for the type of tank gauging apparatus described in my application Serial No. 493,667, tiled March l0, 1955. 'In this case the flexible member S may take the form `of a metallic tape perforated as described in said application for the purpose of transmitting signals of the roof position. The tape in such case provides a loop as indicated at 26 between the pulleys 24, which loop passes beneath a pulley 23 which is carried by a weight 30. As described in said application, a tension is constantly applied to the tape which will maintain it in taut condition, the tension being insuicient, however, to raise the weight 30 from the roof. In operation the tape is pulled downwardly into the gauge 2% lifting the Weight 30 and giving rise to a lirst signal as the weight reaches a predetermined position with respect to the level of the water at B, and then a second signal as the weight is lifted to an arrested position provided by abutments indicated at 32. The position of the tank roof is, of course, determined by the position of arrest of the Weight 30, and it will be evident that correction for roof tilt is effected as indicated above, the means roof position being indicated. The arrangement illustrated also provides for the determination of the depth of water on the roof as described in said prior application.

`It will be evident that variations may be made in details of construction without departing from the invention as defined in the folloing claim:

What is claimed is:

Gauging means for a tank having a tloating roof cornprising a iiexible member, means anchoring one end of said tlexible member at a iiXed level above an edge portion of said roof, guiding means carried by said roof and directing said ilexible member across the roof from said edge portion to a second edge portion of said roof substantially diametrically opposite the iirst mentioned edge portion, guiding means located at a fixed level above said second edge portion, means for maintaining said flexible member taut, and indicating means associated with said exible member, said exible member having free movement past the guiding means carried by the roof and past the last mentioned guiding means so as to move freely between said edge portions of the roof during roof movements, with movements at the last mentioned guiding means substantially proportional to vertical movements of the central portion of the roof irrespective of inclination of the roof.

`Cranmer Nov. 1, 1949 Quist Feb. 26, 1952 

